That Anxiety May Be in Your Gut, Not in Your Head

Gut Bacteria Linked to Behavior: That Anxiety May Be in Your Gut, Not in Your Head

ScienceDaily (May 17, 2011) — For the first time, researchers at McMaster University have conclusive evidence that bacteria residing in the gut influence brain chemistry and behaviour.

The findings are important because several common types of gastrointestinal disease, including irritable bowel syndrome, are frequently associated with anxiety or depression. In addition there has been speculation that some psychiatric disorders, such as late onset autism, may be associated with an abnormal bacterial content in the gut.

“The exciting results provide stimulus for further investigating a microbial component to the causation of behavioural illnesses,” said Stephen Collins, professor of medicine and associate dean research, Michael G. DeGroote School of Medicine. Collins and Premysl Bercik, assistant professor of medicine, undertook the research in the Farncombe Family Digestive Health Research Institute.

The research appears in the online edition of the journal Gastroenterology.

For each person, the gut is home to about 1,000 trillion bacteria with which we live in harmony. These bacteria perform a number of functions vital to health: They harvest energy from the diet, protect against infections and provide nutrition to cells in the gut. Any disruption can result in life-threatening conditions, such as antibiotic-induced colitis from infection with the “superbug” Clostridium difficile.

Working with healthy adult mice, the researchers showed that disrupting the normal bacterial content of the gut with antibiotics produced changes in behaviour; the mice became less cautious or anxious. This change was accompanied by an increase in brain-derived neurotrophic factor (BDNF), which has been linked to depression and anxiety.

When oral antibiotics were discontinued, bacteria in the gut returned to normal. “This was accompanied by restoration of normal behaviour and brain chemistry,” Collins said.

To confirm that bacteria can influence behaviour, the researchers colonized germ-free mice with bacteria taken from mice with a different behavioural pattern. They found that when germ-free mice with a genetic background associated with passive behaviour were colonized with bacteria from mice with higher exploratory behaviour, they became more active and daring. Similarly, normally active mice became more passive after receiving bacteria from mice whose genetic background is associated with passive behaviour.

While previous research has focused on the role bacteria play in brain development early in life, Collins said this latest research indicates that while many factors determine behaviour, the nature and stability of bacteria in the gut appear to influence behaviour and any disruption , from antibiotics or infection, might produce changes in behaviour. Bercik said that these results lay the foundation for investigating the therapeutic potential of probiotic bacteria and their products in the treatment of behavioural disorders, particularly those associated with gastrointestinal conditions such as irritable bowel syndrome.

The research was funded by grants from the Canadian Institutes of Health Research (CIHR) and the Crohn’s and Colitis Foundation of Canada (CCFC).

Story Source:
The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by McMaster University, via EurekAlert!, a service of AAAS.

Dr Flores Comments:

It is well known fact that all chronic disease has a mental/emotional aspect. It is refreshing to see that main stream medicine is finally seeing the connection between mind and body and realizing how much impact our digestion has on our mental state. Just think of how many people love to eat chocolate and satisfying foods when they are going through hard times. Food and the way our bodies utilizes it has a huge impact on how we feel emotionally. Therefore, it is important to regularly do clean ups and tune ups on our digestive system to maximize the ability to absorb and use all the nutrients that our brain needs to stay healthy. Happy and healthy digestion will help you keep a happy and healthy mind.

Give your Gut a break! Try out this delicious Quinoa Summer Salad Recipe! Quinoa is a superfood which is also gluten free! Not only is quinoa high in protein, but the protein it supplies is complete protein, meaning that it includes all nine essential amino acids. Not only is quinoa’s amino acid profile well balanced, but quinoa is especially well-endowed with the amino acid lysine, which is essential for tissue growth and repair. In addition to protein, quinoa features a host of other health-building nutrients. Because quinoa is a very good source of manganese as well as a good source of magnesium, iron, copper and phosphorus, this “grain” may be especially valuable for persons with migraine headaches, diabetes and atherosclerosis.

First, rinse your quinoa in a sieve (it’s tiny so the usual colander might not do).Cook the quinoa as you would raw rice: in 2 and 1/4 to 2 1/2 cups fresh salted water, covered, until all of the water is absorbed.I use my rice cooker to do this. The quinoa turns out fluffy, tender and perfect.Scoop the cooked quinoa into a bowl and add the rest of the ingredients, tossing lightly with a fork until combined.Taste test and adjust seasonings.Cover and chill- the longer, the better. In fact, I think this salad tastes better the second day- so plan ahead and make it the day before.Makes 4-6 servings.